Telephone answering system and apparatus including improved ring responsive circuitry for selectively connecting and isolating the system from the telephone line

Claim 1

In a telephone answering system for responding to telephone messages received over a telephone line and which comprises an announcement storage means and a message storagE means and respective associated transducers, and which further comprises first and second means for driving said announcement storage means and message storage means respectively relative to said transducers for producing a recorded announcement from the announcement storage means in response to an incoming telephone call and for subsequently recording a message from the calling party on said message storage means, and which further includes first control circuit means for activating said announcement storage driving means in response to said incoming telephone call to produce said recorded announcement for transmission over the telephone line to the calling party during a first time interval, second control circuit means coupled to said announcement storage means for activating said message storage driving means at the termination of the announcement so as to initiate the recording of the aforesaid message from the calling party on said message storage means during a second time interval, third control circuit means for deactivating said message storage means so as to terminate the recording of the aforesaid message on said message storage means, and an input/output circuit coupled to said announcement storage means for introducing the announcement thereon to the telephone line and coupled to said message storage means for introducing the message from the calling party thereto; the combination of: a ring signal sensing circuit, a first relay switch connected to said ring signal sensing circuit to be actuated thereby to connect said input/output circuit to the telephone line in response to a ring signal received over the line, electric circuitry connected to the telephone line and including capacitive coupling means presenting relative low impedance to said ring signal to pass said ring signal to said ring signal sensing circuit so as to cause said ring signal sensing circuit to actuate said first relay means, and said electric circuitry presenting relatively high impedance to other signals received over the telephone line to attenuate said other signals and thereby prevent said other signals from reaching said input/output circuit, a second relay switch connected to said telephone line and responsive to the activation of said first relay switch to disconnect said high impedance circuitry and to connect said input/output circuit to the telephone line so as to cause message signals received over the telephone line to be introduced to said input/output circuit, and a control circuit connected to said input/output circuit and responsive to a change in signal level on the telephone line to de-activate said second relay switch and disconnect and isolate said input/output circuit from the telephone line should communication with the calling party be interrupted during the first or second time interval.